Moonlight has opened its outdoor summer season with a production so smart, polished, and accurate you’d think they’ve assembled an all-star team.

And in a way, they have. Brad Bradley — ahem, from San Diego — was part of the multiple Tony Award-winner “from day one.” An original member of the Broadway cast, he knows Monty Python’s deliriously whacko take on King Arthur — and fellow San Diegan Casey Nicholaw’s original choreography — inside out.

Not only that, Moonlight is also using the sets, costumes, and cartoony projections from the Broadway show.

The pre-show set’s such a gutsy choice, it must rank among the Great White Way’s ugliest sights: stone castle walls and a tall, spikey gate, both dead drab brown. They look unfinished, as if the designer quit the project in despair.

Danny Gurwin and Christine Hewitt in Spamalot at Moonlight Amphitheatre.

Jump almost immediately to green-tree-drenched Finland, where villagers in Christmas-colored costumes sing the “Fisch Schlapping Song” and spin and slap each other.

But wait, the Historian said “England,” not Finland — and we’re off.

John Du Prez and Eric Idle based the musical on the 1975 film, Monty Python and the Holy Grail, a low-budget masterpiece of inanity and irreverence. The Lady in the Lake told Arthur he should become King and rule all the Britons.

So he and his Sancho Panza-like sidekick, Patsy, mimic riding horses, to the tune of clacking coconuts, and proselytize for a united England. Along the way they confront some of the most gruesome sights imaginable: monks banging their foreheads in penance, victims of the plague (including one who may be in recovery); and most bizarre: knights who say “ni”; and — “fetchez la vache” — a cow-tossing French sentinel.

Spamalot is nuts — and wonderful. It verges on capital offenses: the song “You Won’t Succeed on Broadway” may offend Jews (since the song claims you won’t succeed if you aren’t), but they also may offend Christians when they take the English expression “God’s feet” literally, and the almighty’s huge feet descend from above.

At the same time, Spamalot wages all-out war on hype and pomposity. You can hear the Balloons of Pretension popping throughout.

And also hear Monty Python having their cake and devouring it too. One of the most amazing tunes, “The Song That Goes Like This,” is a hard-edged parody of the rousing, Act one anthem (“a sentimental song/That casts a magic spell/They all will hum along/We’ll overact like hell”).

Especially as sung by Danny Gurwin and Christine Hewitt. Their rocket-like voices shoot two ways: while the lyrics tear the tune to shreds, the music is, in fact, quite stirring, and heroic, and “let’s save the world!”

After a while, the movie suffered from “The Rocky Horror Syndrome.” You couldn’t sit in a theater and hear it over the countless fans shouting every word in sync. To free the musical from mass echolalia, Du Prez and Idle include full-scale production numbers, as when The Lady and the Lake’s “Laker Girls” — that’s right, LA’s near-defunct hoopsters — sing/dance a pep/chant. Moonlight’s excellent show handles each with precise aplomb.